Abstract:

Background Hormonal contraceptives are used widely but their eff ects on HIV-1 risk are unclear. We aimed to assess
the association between hormonal contraceptive use and risk of HIV-1 acquisition by women and HIV-1 transmission
from HIV-1-infected women to their male partners.
Methods In this prospective study, we followed up 3790 heterosexual HIV-1-serodiscordant couples parti cipating in
two longitudinal studies of HIV-1 incidence in seven African countries. Among injectable and oral hormonal
contraceptive users and non-users, we compared rates of HIV-1 acquisition by women and HIV-1 transmission from
women to men. The primary outcome measure was HIV-1 seroconversion. We used Cox proportional hazards
regression and marginal structural modelling to assess the eff ect of contraceptive use on HIV-1 risk.
Findings Among 1314 couples in which the HIV-1-seronegative partner was female (median follow-up
18·0 [IQR 12·6–24·2] months), rates of HIV-1 acquisition were 6·61 per 100 person-years in women who used
hormonal contraception and 3·78 per 100 person-years in those who did not (adjusted hazard ratio 1·98, 95% CI
1·06–3·68, p=0·03). Among 2476 couples in which the HIV-1-seronegative partner was male (median follow-up
18·7 [IQR 12·8–24·2] months), rates of HIV-1 transmission from women to men were 2·61 per 100 person-years in
couples in which women used hormonal contraception and 1·51 per 100 person-years in couples in which women
did not use hormonal contraception (adjusted hazard ratio 1·97, 95% CI 1·12–3·45, p=0·02). Marginal structural
model analyses generated much the same results to the Cox proportional hazards regression.
Interpretation Women should be counselled about potentially increased risk of HIV-1 acquisition and transmission
with hormonal contraception, especially injectable methods, and about the importance of dual protection with
condoms to decrease HIV-1 risk. Non-hormonal or low-dose hormonal contraceptive methods should be considered
for women with or at-risk for HIV-1.